Adjustable ground clamp



Dec. 13, 1960 R. M; WILSON 2,964,728

ADJUSTABLE GROUND CLAMP Filed Nov. 24, 1958 nun 10; I l at gamma!!! INVENTOR BY QQQKPM ATTORNEY United Pat t ADJUSTABLE GROUND CLAMP Robert M. Wilson, Battle Creek, Mich., assignor to Dare Products, Incorporated, Battle Creek, Mich., a corporation of Michigan Filed Nov. 24, 1958, serrNo. 776,081

3 Claims. (Cl. 339-266) The present invention relates broadly to clamping devices, and in its more specific phases to a new and improved ground clamp for use with various kinds of electrical appliances and systems.

Ground clamps of the most commonly used form are of the wrap-around type with a different size required for each size rod or pipe around which they are clamped, and all forms of ground clamps are generally either difficult to mount as well as adjust, or have very limited adjustment capabilities, and often have poor capability of positive grounding on the metal member to which they are fastened. It was a recognition of these problems and the lack of a thoroughly satisfactory commercial product on the market which will solve such problems, and do so at a very low cost, which led to the conception and development of the present invention.

Accordingly among the objects of the present invention has been the provision of an exceptionally simple and inexpensive clamp, quickly and easily applicable, and capable of establishing a reliable ground connection.

Another object has been to provide a novel construction formed primarily from sheet metal stampings and yet being amply strong to permit thorough tightening without bending.

, A further object is to provide a ground clamp which has an exceptionally wide range adjustment capability.

Still further objects and advantages of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, consists of the clamping means hereinafter fully described and particularly pointed out in the claims, the annexed drawing and the following description setting forth in detail certain means for carrying out the invention, such disclosed means illustrating, however, but one of various ways in which the principle of the invention may be used.

In the annexed drawing:

Figure 1 shows a partially sectioned side elevation of the improved ground clamp of the present invention mounted on a pipe.

Figures 2, 3, 4, and are edge views looking in the directions of the arrows 2, 3, 4 and 5 of Figure 1, respectively.

Figure 6 is an enlarged fragmentary perspective view of an end portion of a preferred form of the improved ground clamp.

The construction disclosed has been commercially proven to be advantageous from all standpoints and is therefore preferred. However, attention is invited to the possibility of making variations within the obvious spirit and intent of the invention as set forth in the drawing and description presented herein.

Two substantially parallel clamping bars 10 and 11, Figure 1, are provided for transverse disposition at opposite sides of a grounding member G, such as a metal pipe or rod. The bar 10 has substantially parallel side flanges 10a integral with a web 10b. The bar 11 has similar side flanges 11a integral with a web 11b. All of the flanges 10a and 11a are symmetrically notched at 12 to provide them with sharp corners 13 to engage and positively grip the ground member G.

' One'end of the web 10b is formed with a notch 14; and the corresponding end of the web 11b is provided with an integral arm 15 extending through said notch 14. Opposite edges of the arm 15 are symmetrically notched at 16 to provide them with spaced teeth 17 to abut the outer side of the web 1012 at opposite sides of the notch 14; and portions of said web 10b are outwardly bent slightly to provide stops 18 to abut the outer sides of the teeth 17 and thereby prevent the arm 15 from accidentally moving from the notch 14 during and after tightening of the clamp on the grounding member G.

The end of the web 10b remote from the notch 14 is formed with an opening 19, the wall of which is elongated and threaded. The corresponding end of the web 11b has a slot 20. A clamping bolt 21 extends loosely through the slot 20 and is threaded through the opening 19. One end of this bolt has a slotted head 22 to be engaged by a screw driver to tighten the clamp. By threading the elongated opening 19, and forming opening 20 as a slot, an unobvious flexibility of the assembly for adjustably fitting various sizes of ground members G is attained while eliminating the need of an extra nut on the end of the bolt 21, and producing a more stabilized assembly than where this opening 19 is not threaded. The other end of the bolt 21 is provided with a washer 23, a lock washer 24 and a nut 25 for anchoring a ground wire W to the clamp. The ground Wire W is shown as having a terminal 26 surrounding the bolt 21, and tightly grippable when nut 25 is tightened, but the Wire end could simply be bent around said bolt and gripped to the clamping bar 10 by means of nut 25 and lock washer 24.

It Will be seen from the foregoing that a simple, stable, and effective ground clamp has been provided. The clamp may be easily separated and opened for passage around the grounding member G, easily reassembled and adjusted according to the diameter of this member, easily clamped in position, and easily connected to the ground wire. Attention is also again invited to the possibility of making variations within the obvious spirit and scope of the invention as shown and described.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the clamping mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. A ground clamp comprising two opposed, substantially parallel, one-piece clamping bars for disposition at opposite sides of a grounding member, one end of one of said bars having an open-ended notch, an arm integral with and extending from the corresponding end of the other of said bars and substantially perpendicular thereto, said arm extending through said notch of said one of said bars and having side edges with substantially symmetrically spaced teeth on the opposite sides thereof in position to abut the side of said one of said bars remote from the other of said bars and at opposite sides of said notch, the other ends of said bars each having an opening and said openings being substantially alined, the opening of one of said bars having suitable threads, and a clamping bolt extending through said alined openings of said clamping bars and operative with said threads to draw said bars into clamping relation with the grounding member, said one of said bars also having stops at the open end of said notch to abut said teeth when they are in engagement with the opposite sides of said notch and prevent accidental movement of said arm from said notch after said bolt has been at least preliminarily tightened.

2. A structure. as specified in claim 1, in which said bolt fits and passes through the other of said openings which is not threaded and is in the form of a slot extending lengthwise of one of said bars, and said bolt is provided with a nut for anchoring a ground wire to the ground clamp after same has been fastened to said grounding member.

3. A structure as specified in claim 1, in which each of said clamping bars has substantially parallel side flanges projecting in the same direction from a web, the side flanges of one clamping bar extending toward the side flanges of the other clamping bar, said openings being in the webs of the two clamping bars, respectively, said 15 '4 notch being in the end of the web of said one of said clamping bars, said stops being formed by outwardly extending portions of this web at opposite sides of said notch, the free edges of said flanges of each of said bars having notches substantially in alinement with each other to provide them with sharp corners to engage and grip the grounding member.

References Cited in the file of this patent UNITED STATES PATENTS 1,900,894 Barnes et a1. Mar. 14, 1933 2,112,053 Thomas Mar. 22, 1938 2,547,932 Downs Apr. 10, 1951 2,610,816 Vote Sept. 16, 1952. 

